According to research done by a team at the Department of Medical Bioscience in Umeå University in Sweden, people who exhibit signs of ongoing depression and chronic stress possess shorter telomeres in their white blood cells, which have been previously shown to accelerate the aging process in an individual. This short telomere length has been attributed to increased levels of the chemical cortisol – increased cortisol production is indicative of exposure to chronic stress.
The study utilized 91 patients with reoccurring depression and 451 healthy controls. While telomere length was found to be shorter in the depressed patients, stress regulation in the healthy controls was tested as well, and showed that stress can just as easily lead to excessive cortisol production and short telomeres. “The test revealed that cortisol levels indicative of chronic stress are associated with shorter telomeres in both depressed and healthy individuals,” says Mikael Wikgren, a doctoral candidate in the research group. The study attributes short telomeres to depressed people specifically, due to the fact that more depressed people than healthy people have disturbed cortisol regulation, though chronic stress is just as likely to overproduce cortisol as depression. This further shows the major role that stress can play in depressive disorders.